[Executor]

Hello Foodstamp,
Giving your nation a go and I though I'd give a few quick observation.

The nation has easy access to stealthy troops but no commanders to lead those troops. The stealthy commanders have only leadership 10 which will suffice only for 1 PD provinces sadly.
There's always the option of giving magic item leadership boosts, but the nation has no access to death for the rod of the leper king, and only access to S1 (with no nation astral gem income), thus making it hard to forge crown of command for this purpose, even for those who'd consider this option since forging items for this purpose is wasteful..
I suggest boosting leadership to 40 for one of the stealthy commanders. Stealthy troops seem rather unusable given the current state.

And second, Thunderbirds. At first they seemed awesome to me. Sacred, stormflyers, immortal, even their price seemed great cause of the added number due to magic path however they are a huge disappointment.
They have terrible stats and no protection, any single hit kills them. Eventually after dozens of battles they'd get some extra attack and defence due to immortality but that's not enough.
They have higher somewhat strength but a no strength attack which is quite weak, so they can't kill anything in the first (and only) round they live.
They are sacred, but a bless approach is a bad way to go for them. The nation has no need for a bless given the lack of sacred troops and the only bless that seems viable for them is a water bless which is contradictory to your bears given their berserk. So bless is not an option either.

At first I thought I'd abuse them with having an A9 pretender spamming them from the start, but given that 40 thunderbirds lose easily to militia I'd say even that is a bad option.
So IMO, they are extremely overpriced at 12 for 2+ ( they're not worth even summoning with a boosted mage or a high level pretender) and have quite terrible stats.

Just compare them to vampires. High strenght with a drain attack, fliers, regeneration, more than double HP.
Vampires are even cheaper than Thunderbirds, incredibly better, stronger, better stats and much more easily massed.

I can provide more feedback as I go along, these is just something I noticed first.